High-Speed, Ultrahigh-Resolution Spectral-Domain OCT with Extended Imaging Range Using Reference Arm Length Matching

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Spectral-domain optical coherence tomography (SD-OCT) is crucial for retinal imaging.
• Ultrahigh-resolution (UHR) imaging offers enhanced detail but faces range limitations.
• Improving speed and range is essential for clinical applications.

Purpose of the Study:

• To develop high-speed, extended-range UHR SD-OCT.
• To demonstrate scan protocols for clinical retinal imaging.
• To enhance visualization of retinal structures.

Main Methods:

• Developed an 840-nm UHR SD-OCT system with 150-nm bandwidth.
• Implemented dynamic reference arm length matching (ReALM) to extend axial imaging range.
• Utilized high-definition raster and cube volume scan protocols with motion correction.

Main Results:

• Achieved 2.7 µm axial resolution with a 1.2-mm imaging range at 128- and 250-kHz A-scan rates.
• Dynamic ReALM maintained the retina within the imaging range over wider fields of view.
• Visualized outer retinal features, including photoreceptor layers and Bruch's membrane, with observed alterations in AMD.

Conclusions:

• Technological advancements, including dynamic ReALM, significantly improve UHR SD-OCT performance.
• Enhanced imaging capabilities improve clinical usability and diagnostic potential for retinal diseases.
• Simplified workflow and reduced imaging times are expected.